


Big Boy Games

by preyforme



Series: Cassy Baby [1]
Category: Supernatural
Genre: Anna gifts her baby brother to her boyfriend, Bathing/Washing, Blow Jobs, Dry Orgasm, Extreme Underage, Extremely Underage, Giggling, Innocent Castiel, Kissing, Masturbation, Multi, Naughty Touches, Rimming, Sibling Incest, Underage Kissing, Underage Sex
Language: English
Status: Completed
Published: 2014-08-17
Updated: 2014-08-17
Packaged: 2018-02-13 12:00:03
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,587
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2149968
Author URL: https://archiveofourown.org/users/preyforme/pseuds/preyforme
Summary: <blockquote class="userstuff">
              <p>Anna plans a threesome for her and Dean on their six month anniversary...  But she's stuck babysitting her four year old brother.  Her plans are ruined.  Or are they?</p><p>**EXTREMELY UNDERAGE SEX**  PLEASE READ THE TAGS!</p><p>Based on spn-kinkmem request: "Teen Dean likes sucking his gf's brother's tiny prick. He's so precious. So gorgeous when he orgasms (dry of course). He likes kissing the boy too, fucking his mouth with his tongue. Cas always giggles and makes yummy sounds. Maybe rimming happens too?"</p>
            </blockquote>





	Big Boy Games

**Author's Note:**

> This story involves sexual acts between two teenagers and a four year old. Although it is "consensual" in the way that he doesn't resist, no one that young can actually give consent. IF YOU DO NOT WANT TO READ ABOUT SEX BETWEEN A CHILD AND TWO ADULTS PLEASE LEAVE. The internet is full of wondrous places, perhaps try this site; http://theworstthingsforsale.com/. It's hilarious.

Dean’s been dating Anna for a few months now, which is longer than anyone, including him, thought it would last. To be honest, he only asked her out because she was a Pastor’s daughter and he thought it would be fun to corrupt her, take her cherry, and dump her. Boy did he underestimate her.

It was probably having to be so pious all the time that led to Anna being so wild. She wasn’t a virgin, not by a long shot, and she was into some kinky stuff. She liked letting Dean fuck her in public, they’d almost gotten caught so many times. He’d pull up her skirt, push her panties to the side and plunge into her sopping wet pussy anytime he wanted to. They went to a nice restaurant with her parents and he fingered her all throughout dinner. She was wilder than he ever could have imagined. 

On their six month anniversary he expected a night to remember. Anna told him about a freshman cheerleader with a crush, said the girl had been thrilled about being invited for a threesome. When Anna called to tell him she described, in vivid detail, how she was going to eat the girl out before Dean fucked her. Best. Girlfriend. Ever.

But when Dean got to her door she was frowning, “I was just about to call you. My parents had an emergency at the church and I gotta watch Cas tonight.” She pouted, leaning into Dean’s personal space, whispering, “I don’t want you to fuck her without me.”

Dean leaned in to press a chaste kiss to her lips, they were on her front porch after all, and she had a reputation to maintain, “I wouldn’t want to.” He put his hands on her hips, looking up at her, “Can I hang out for a little bit?” he whispered softly, “We could have some fun after Cas goes to bed.”

“I’m sure my parents wouldn’t mind, they trust me to obey the rules.” She held up her hand with the promise ring on it, “They were so impressed that you respected my desire to wait until marriage, they said you’re welcome anytime.” Dean had said that with two fingers pushed up inside her pussy thanks to the extra-long table cloth but they didn’t need to know that.

He stepped inside the door, kicking off his boots as Castiel tore around the corner, “Anna! Anna! The DVD player isn’t working!” Dean grinned down at Anna’s four year old brother, he was just as beautiful as his big sister but in a totally different way. His hair was dark and falling across his forehead, his crystal blue eyes were wide and full of excitement. And those lips. Cas was going to be a heart breaker when he grew up. “Oh! Hi Dean!”

Dean reached over to mess up Castiel’s hair, laughing when the boy ducked out from under his hand. “Hey Cas, you’re on your best behavior for your big sister, right?” 

“Yes. I’m always good!” he grinned, looking back over at his sister, “Right Anna?”

She rolled her eyes, but it was a playful gesture, she loved spending time with him, she just wished it hadn’t interrupted her plans.

Or had it?

She bit her lower lip and leaned into Dean’s ear, “Wanna give him a bath?” Her words were soft and breathy against his ear, “He’s even cuter than the cheerleader.”

Dean swallowed thickly, he’d never thought about Cas like that before. But he was beautiful. “How long are your parents gonna be out?”

Anna smirked. “Hours.”

Dean crouched down so he was eye level with the little boy, “Cas, buddy. I think it’s time for a bath.”

“But I just took one yesterday.” He said with a pout, “I wanna watch Cars.”

The pout broke any resolve he had left. He was going to defile the precious boy. He reached over and traced Cas’s lower lip, “Don’t pout little man. You can watch Cars if you want. But…” he drew the word out, obviously piquing Castiel’s interest, “I was thinking we could play a big boy game after you’re all clean.”

Castiel’s beautiful blue eyes lit up and he nodded quickly, “I’m a big boy. I wanna play big boy games!”

“Well then let’s go buddy.” Dean said laughing. Cas took off running towards the bathroom and he turned to Anna, “You’re giving me your little brother for our anniversary?” He grabbed Anna’s hand and pushed it against the crotch of his pants where his dick was already starting to get hard, “You’re sick.” He leaned in and kissed her, mumbling against her mouth, “I don’t think that I could love you anymore than I do right now.”

Anna laughed against his mouth, taking his hand and sliding it under her skirt where she wasn’t wearing any panties. She started to grind down against his fingers, showing how wet she was. “How about now?”

Before he could answer he heard Cas calling for them and he nodded towards the bathroom, “Let’s not keep him waiting.”

Cas was already trying to pull his shirt off, but he’d got stuck in his excitement; he had one arm out of the shirt, but it was tangled around his other arm and his head. Dean laughed and knelt down next to Cas, “Gotta slow down buddy. I’ll help you get undressed while your sister gets your bath ready.”

He stripped Cas out of his shirt, noting how slim his tiny body was. Dean could barely remember when Sammy was this little and he hadn’t been around a lot of other kids. His nipples were barely noticeable, so small and when Dean brushed a thumb across one casually Cas even didn’t react. He was too busy struggling with the button on his jeans, “I don’t like these, they’re too hard to open.”

“That’s what I’m here for, remember? I said I was gonna help.” He unbuttoned the jeans and let them fall to the floor. Cas leaned in and held onto each of Dean’s shoulder’s for balance as he stepped out of the pants. Dean was so close to his baby smooth skin, he wanted to lick a stripe up Cas’s neck to his ear but he didn’t want to scare the little boy. When Cas shook his pants off he reached to push his briefs down but Dean stopped him, “Wait Cas.” He wanted to look the boy over; the scrapes on his knees, his round little tummy, the picture of Spiderman over his crotch. Dean wanted to eat him whole.

“I can do it myself.” Cas said, a little annoyed, obviously wanting Dean to see him as a big boy.

“Let him help Cas, Dean doesn’t get to come over and play with you very often.” She winked over her shoulder at Dean when she said the words _play with you_. 

Cas just shrugged, “Okay.”

Dean hooked his fingers in the Spiderman briefs and pealed them down slowly to reveal the smallest dick he’d ever seen. Dean expected him to be totally hairless and underdeveloped, but he couldn’t believe how _little_ he was. He couldn’t help but touch. He ran his thumb over the shaft, little Cas shivered and looked from his tiny dick up to Dean, “Momma said no one’s ‘suposta touch me there Dean.”

Dean smiled and leaned it to press a kiss against Castiel’s forehead, “That’s only to stop people from hurting you. I’m not hurting you, am I buddy?” 

Cas looked a little uneasy but shook his head.

Anna crouched down next to her little brother, “You know I wouldn’t let anything back happen to you, right Cas? I’m your big sister, I’m here to protect you.” He tapped the tip of his nose with one of her perfectly polished nails, which immediately made him smile, “Me and Dean are gonna take really, really good care of you.”

Cas slipped into the tub and Anna immediately started washing him, she gave him his bath most nights, there was nothing different about this. Except that Dean had moved behind her and pushed her skirt up a little, so he could expose her pussy. He wanted to take his cock out and at least rub it against her, but he couldn’t be sure that Castiel wouldn’t see and he didn’t want to scare the little boy. Instead he just slowly fingered her while she washed her brother. Dean reached for the washcloth, “I’m gonna getcha clean buddy.” His free hand worked the rag over Cas’s tiny penis while he continued to push into Anna, twisting his wrist so he could play with her clit, he was intoxicated by the idea of fondling them both at the same time. 

Cas didn’t even seem to notice Dean releasing the cloth and exploring his tiny cock and balls, instead he focused on the boats he was playing with. He leaned in to whisper in Anna’s ear, “I want you to come while I have two fingers inside your pussy and two on your baby brother’s balls.” Dean had barely finished speaking when she came. She always had a weakness for dirty talk.

“Anna? Are you okay?” Cas looked concerned, which was an adorable look for him, dark hair plastered on his forehead, toy boats in each hand, tiny prick hard between his soft thighs. 

“Better than okay.” She said with a smile, grabbing a towel while Dean let the water out of the tub. 

Cas let his sister wrap the towel around him before taking off towards his bedroom, “I’m gonna get my jammies on then we can play our game!”

Dean stood in the doorway of Castiel’s bedroom, thankful that he had a moved up from a toddler bed to a twin bed. Even in a twin bed it was going to be a tight squeeze for all three of them. “No buddy, this is a big boy game. You don’t have to put jammies on.” 

Cas had a pair of Cars pajamas in one hand and he was holding up his towel with the other, “What do you mean?”

Sitting on the bed he patted the comforter, “Come sit with me.” He couldn’t believe he was going to defile his girlfriend’s four year old brother on a Batman sheet set. “Sometimes grown-ups play secret games. Games you can’t tell anyone else about.” He looked very seriously into little Castiel’s eyes, “If we play our game you can’t tell anyone, they’ll take you away to live with another family. Your mom and dad and Anna would miss you so much.” Dean pretended to think for a moment, “Actually, we better not play, you might not be big enough.”

Castiel’s eyes went wide, “I am! I am! Please Dean!!”

He couldn’t believe he had this beautiful little boy begging him to do vile things to him. “How about this? We start off slow and you can tell me to stop any time. Right Anna?”

Anna couldn’t take her eyes off of her boys. Her gorgeous boyfriend and her precious, dripping wet baby brother, “Trust me Cas, this is a _super_ fun game. Me and Dean play _all the time_.”

Castiel looked really excited by the prospect of playing a game that Anna and Dean played together, “Cool! How do we start?”

Dean reached down to adjust himself in his pants, trying to be as casual as possible, “First, you start with a kiss.”

Cas scrunched his nose up, “A kiss? Kissing is gross.”

“Not when I do it.” Dean said with a grin, leaning in to press his lips against Castiel’s, “Not so bad right?” Cas nodded a bare shoulder, “Okay so this time, I want to touch tongues. It’s like your tongue is giving my tongue a high five.” 

Castiel looked over at Anna, but not with fear or apprehension, just confusion. Anna crossed the room and kneeled in front of them, “It’s simple Cas, like this.” She reached up and cupped the back of Dean’s head, flicking her tongue against his lips before pushing it slightly between Dean’s lips, “Now you try.”

Dean leaned down towards the little boy and Cas moved in, licking Dean’s lips before pushing his tiny tongue into the teen’s mouth, “Like that?” Dean swore he could feel his dick leaking in his pants, “You’re doing real good buddy, now I’m going to try it too.” He ran the tip of his tongue along Cas’s plush lips, at only four he was already sexy as hell, then he slowly pushed his tongue inside his warm, wet mouth. His tongue felt huge, it was obviously an enormous intrusion and it just made everything hotter. He could even hear Anna whimper breathlessly next to him. “You gonna give your big sister a kiss too?” Dean teased gently, letting Castiel make up his own mind. 

The four year old leaned in and kissed Anna’s lips, pushing his tiny tongue into her mouth as well. She tried to coax his tongue into her own mouth, sucking on the tip before releasing him, “Good job Cas. I’m so proud of you.” She kissed him again, this time just a quick brush of lips, “You’re going to win this game for sure.”

Dean was enraptured by the way Anna was talking to her little brother, the way she was sucking on his tongue, he wanted to videotape it, watch it over and over again. “Now lay down, I’m gonna show you the next part.” He situated Cas in the middle of his bed and slowly took the towel away, left with nothing but a perfect, tiny body for him to explore. Castiel’s dick had gotten soft since getting out of the tub but Dean knew it would just be a matter of minutes before he changed that, “You are so beautiful.” He leaned down and pressed his mouth to Castiel’s, massaging their tongues together until the little boy needed to breathe. He looked over at Anna, grinning at her, “Isn’t he beautiful Anna?”

“You sure are.” She wanted her baby brother to relax a bit so she leaned in and blew a raspberry on his tummy, “You must get that from me!”

Cas giggled and squirmed around on his bed, looking between Anna and Dean, “What’s next?”

“What’s next?” Dean laughed, reaching down to tickle the little boy up his sides, body so small Dean could almost count all his ribs, “More kissing!” 

With Cas twisting and turning Dean leaned down and started blowing raspberries too, only then he would let his tongue dance along the soap scented skin. He started at the slope of Cas’s neck, moved down and planted one right over his nipple, Cas kept giggling as Dean’s tongue worked the tiny nipple hard. He slid down to Cas’s belly and let the tip of his tongue press into the little boy’s bellybutton. Cas’s laughter was slowing, but only because Dean was spending more and more time licking at the boy’s soft skin.

“Dean. That tickles!” he said breathlessly, needed to regain his breath from laughing so hard. 

Gently Dean eased Cas’s legs apart, he could feel Cas tense up a little bit so he leaned in and blew a raspberry against his inner thigh, causing him to erupt in giggles again. Then he slowly kissed a trail to Cas’s soft, little dick. He ran his tongue along the shaft and inhaled the scent of bubble bath and four year old crotch. He heard Cas’s tiny little voice, “Anna?”

Anna ran a hand through his hair, “Feels good, doesn’t it Cassie? I like when Dean kisses me there too.” Castiel looked relieved at Anna’s words, knowing this was a game that she and Dean played, he liked being included in their games. “Feels weird.” He said softly, giggling a little bit when Dean’s fingers toyed with his balls. She leaned in and kissed him again, licking at his soft lips, nipping at the tip of his tongue playfully, loving the way he laughed when she sucked on his tongue.

“Anna, look at this.” He mumbled against Cas’s skin, kissing the inside of his thigh because he just couldn’t bear to stop touching, “Look at his little stiffy.” Dean held Cas’s tiny dick between his thumb and forefinger, rubbing it slowly, loving the way Cas spasmed under his hand.

She bit her lower lip, hand reaching down to brush her thumb over the head of his dick. Part of her wished he was older so she could see him leaking, so she could taste him. But she was in no hurry for him to grow up, she liked him just the way he was. She dropped a hand between her own thighs to start jerking off again, glad for the skirt so Cas couldn’t see what she was doing. “Betcha could get his whole package in your mouth at one time.” She whimpered, loving the way Dean’s hands dwarfed Cas’s miniature cock.

He knew it would be an easy task, just as he knew that Anna only brought it up because she wanted to see it. Dean ran his tongue up and down Cas’s tiny nuts, sucking them into his mouth as Cas erupted in giggles again, reaching down to fist his tiny hands in Dean’s hair, “Tickles Dean!” Dean just grinned against his skin and took his cock and balls into his mouth, sucking on both. He made sure to press his tongue to the underside of his prick, it drove Cas crazy, “That makes my willy feel funny!” 

“Funny good or funny bad?” Dean asked after releasing the boy’s private, only to start licking and sucking on the shaft again. 

“Good!” Cas moaned out, but the question didn’t really need an answer, his tiny heels were digging into the covers as he bucked up into Dean’s face, trying to get more contact against his tiny body. 

Dean’s mouth sunk down even lower, kissing his balls and perineum, “Want me to show you something that feels even better?” Without waiting for a response he brushed his tongue against Cas’s tiny opening. He reached down to hold Cas’s tiny ass in his hands, pulling the baby soft globes apart as best he could. His genitals were tiny but his asshole was almost non-existent. He pressed his tongue against the opening, not breaching it yet, just waiting to see how Cas would react.

His little body went rigid but Anna was there to thread her fingers through his hair, “This is my favorite part, this is the best place to get kissed on your whole body!” Her delicate hands moved over his chest, pinching his nipples playfully, getting him to laugh again as she kissed at his tummy, “Just relax Cas, if you don’t like it, Dean’ll stop baby.”

With Dean now holding up half of his tiny body, Anna had perfect access to his tiny pick. She didn’t hesitate to take it in her mouth, tongue working over every inch. She loved blowing Dean, loved feeling the head of his cock pushing against the back of her throat, but there was something amazing about a dick so small. About knowing they were the first people to ever take pleasure from Cas’s slight body. She hollowed her cheeks, sucking on his tiny prick as she fucked a third finger into her pussy. She came for the second time that night with her lips wrapped around her brother’s four year old dick.

She pulled back from his dick, wanting to watch as Dean pressed his tongue into Castiel’s tight opening. Anna wasn’t sure how much of his tongue, if any at all, was going to get in there but she liked watching him try. She looked over at Castiel’s face and saw that he was in Heaven, he was twitching under Dean’s mouth, making noised she’d never heard before. He was whimpering and moaning, it was a gorgeous sight.

Dean pulled away regretfully, he could eat out the tiny boy for hours but he was clearly overstimulated. He needed to come and Dean knew he would beg if he even knew what to ask for. He pressed one figure against Castiel’s opening, just left it resting against the spit-slick hole and his other hand jerked the boy off, watching as he floundered and eventually came. Nothing came out of his dick, Dean was a little surprised, he knew little boy’s couldn’t ejaculate but he thought _something_ would dribble out of his dick. 

Little Castiel’s hair was a wreck, and his body was limp, blissed out of his mind, his soft little dick limp against his body. He looked like a little angel.

“What was _that_?” he asked breathlessly.

Anna chuckled and kissed him on the forehead, “That means you won, sweet boy.”

Dean hated putting clothes on the boy but he couldn’t leave any evidence of what they’d done. Cas could barely hold himself up as they dressed him, clearly drained from his first baby orgasm. They tucked him into bed where he fell asleep immediately. Anna was still kneeling on the ground so Dean pushed her face into the mattress, pulled his aching cock out of his pants and shoved into her soaking wet pussy without hesitation. He thought of all the things he wanted to experience with the little boy, all the dirty things he wanted to introduce him to. He leaned down into Anna’s ear and whispered, “We are going to make great parents one day.”


End file.
